Such systems generally include a rectangular frame, which can be mounted to an opening formed in the roof of a vehicle. This frame has guides for a plurality of carriages to slide on, these being connected to the closure element/elements provided for selectively closing the opening in the roof. In order to do this, transmission means are provided for transmitting to the carriages movement imparted by a motor, by means, for example, of chains, cables belts or the like.
In conventional systems it is common for an openable roof configuration designed for a particular model of vehicle not to be adaptable economically for use on a different model. This problem is particularly acute in boats, where the difference in dimensions between one model and another can be considerable and where operating requirements can also be different, with regard for example to the method by which the closure elements forming the openable roof are moved. As a result, adapting any particular openable roof configuration designed for one type of craft for use on another often involves the introduction of expensive modifications or even a complete redesign of the structure.